Lighting unit



p 6, 1958 w. H. BEAUBIEN ETAL 2,852,758

LIGHTING UNIT Filed Dec. 22, 1955 Fig.5 1

lnvemors: WiHicm H. Beaubien John P. Foulds by Their Arro'rney UnitedStats Patent LIGHTING UNHT William H. Beaubien and John P. Fonlds,Hendersonville,

N. C., assignors to General Electric Company, a corporation of New YorkApplication December 22, 1955, Serial No. 554,742

4 Claims. (Cl. 340-74) Our invention relates to lighting units and, morespecifically, to lighting units particularly suited for use in traflicsignal system-s and the like.

It is a general object of our invention to provide a new and improvedlighting unit which is inexpensive, simple in structure, and easilyassembled and disassembled for replacement of parts and for servicing.

It is also an object of our invention to provide a lighting unitcomprising a housing, a reflector and a flexible gasket detachablymounted on said housing and said reflector for positioning saidreflector in said housing.

It is a further object of our invention to provide a lighting unitassembly in which the reflector is supported in the lighting unithousing by a gasket which also engages the lens in the door closure forthe housing to provide, when the door is closed, a tight seal whicheffectively keeps dirt, dust, bugs and moisture out of the resultingoptical assembly.

It is also an object of our invention to provide a construction in whichthe above-mentioned gasket indexes the reflector in one or more desiredpositions in the housing and from which the gasket and reflector may beremoved readily to provide access to an adjustable lamp socket mountedin the reflector and to the wiring enclosed within the housing and inback of the reflector.

Further objects of our invention will appear from the followingdescription thereof. In one embodiment of our invention, the housing ofa lighting unit is provided with an opening in its face and a gasket,which engages the edge of the housing about this opening and likewiseengages the edge of the open mouth of a reflector, providing adetachable support for the refiector in the housing. Indexing meansassociated with the gasket, housing and reflector ensure the properlocation of the reflector in the housing in one or more desiredpositions. The opening in the housing is closed by a door having anopening therein for a lens which has an exposed inner peripheral areaadapted to engage the reflector supporting gasket and means are providedfor holding this door closed over the opening in said housing with saidperipheral area of the lens in engagement with said gasket. Thus, byopening the door, access is readily gained to the interior of thelighting unit for cleaning the reflector and for replacing the lamptherein. This lamp is mounted in a socket adjustably supported at theinner end of the reflector. Furthermore, by releasing the gasket fromthe housing structure, the reflector mounted therein may be removedtherefrom .in order to expose the interior of the housing foradjustingthe lamp socket position in the reflector and for making any wiringoperations which may be required. The indexing means associated with thereflecton'housing and gasket not only ensures a proper assembly of theseparts for the desired positioning of the reflector relative to anobserver and the lens coveringthe reflector but also serves to seal theoptical system including reflector, lamp and lens when the door holdingthe lens is closed. The gasket thus" forms a seal between the lenshaving holes therein for these hinge pins.

Patented Sept. 15, 1958 and reflector and at the same time forms a sealbetween the reflector and the housing in which the reflector is mounted.

Our invention will be better understood and its various objects andadvantages further appreciated by referring to the following detaileddescription taken in connection with the accompanying drawing in whichFig. 1 shows an assembly of our lighting units to form two signal facesat ninety degrees to one another for the display of the usual stop,caution and go signals in each face; Fig. 2 is an exploded view showingthe manner in which the lighting units are assembled and locked inposition relative to one another and their mounting means; Fig. 3 is aperspective view in which the reflector and gasket mounted thereon areshown removed from the housing to illustrate the indexing means employedfor securing a desired assembly of those parts; Fig. 4 is a sectionalview taken along the lines 44 of Fig. 3 to show the relationship of theparts when assembled and with the lens door covering the opening in thehousing; and Fig. 5 is a detail view showing the construction of one ofthe indexing tabs by means of which the gasket is positioned and held inthe housing.

Our lighting unit may be used alone as a one color, one-way signal ortwo or more of our units may be grouped into complete signal faces fororientation in one or more directions. As shown in Fig. 1 of thedrawing, two groupings of three of such units mounted one on top of theother are provided for a two-way signal providing the usual stop,caution and go signals of red,

yellow, and green for each way.

As shown in the drawing, eachunit may comprise a hollow casing orhousing 1 having a cylindrical body portion which is closed at one endand has a circular opening in its other end defined by a body section ofre duced diameter. The door structure comprises a splitring 2 having aconfiguration forming an inwardly directed channel-shaped slot 3 forholding the rim .4 of a lens 5 and a rim 6 which partly overlays. thesection of reduced diameter of housing 1 when the door is closed. Thechannel-shaped slot 3 and rim 6, which is of larger diameter, areconnected with one another through a grooved section 7 of the door whichat the split portion of the ring structure is provided with lugs throughwhich a bolt 8 passes to secure the assembly comprising the doorstructure. The body portion of this bolt rests within groove 7 which inthe assembly serves to hold the nut on the bolt against turning when thehead of the bolt is turned to secure the desired clamping engagement.The flanged edge of a visor 9 is also seated within the channelshapedgroove 3 and thus held in position in the door assembly.

The door structure is attached to the casing of the lighting unit by ahinge 10 formed by a pair of brackets one of which is attached to thehousingand the other of which is attached to the split-ring forming thebody portion of the door. One of these brackets is provided at itsextremities with hinge pins and the other with lugs By deforming thebracket having the lugs for these hinge pins, it is possible todisassemble the hinge and thus remove the door from the housing. Thedoor is held in its closed position by a spring latch 11 which, in thearrangement illustrated, is mounted on the lighting unit housing and hasat its free end a configuration which seats within groove -7 of the doorstructure.

Projecting bosses 12 and 13 of circular section are formed in the topand bottom portions of the cylindrical part of the housing in order toprovide mounting surfaces therefor. The central areas of thesebosses'are formed to provide mating surfaces, one of which is recessedwithin one of the bosses and the other of which projects from the otherboss so that when a unit is assembled with another unit or with asupport member by fitting these bosses together a connection is formedwhich will prevent the entrance of dirt, dust or moisture at the jointbetween them. The central areas of each of these bosses are providedwith wiring holes or openings which, as shown in Fig. 2, are notched atninety degree positions. The parts are held together by clamping Washers14 and 15 having interfitting projections and slots which match inlocation with the notches in the wiring openings above referred to.These clamping washers are held in assembled relation by a bolt 16 whichpasses through centrally located openings therein. Thus, each unit or agroup of units may be rotated around'a vertical axis and firmly lockedat ninety degree positions in perfect alignment with one another andtheir support. The central part of each washer is formed with radialarms which provide spaces between the arms for wires to pass into andout of the units. positions may be provided by suitably notching thewiring openings in the lighting unit housing. Where a terminal board 17is provided in one of the housings of a grouping as shown in Fig. 3, thesupporting bracket therefor may also be held by the bolt which securesadjacent housings together through clamping washers 14 and 15 asprevious ly described.

Various supporting arrangements may be provided for the lighting unitsor their various groupings, and as shown in Fig. l, the two groupings ofthree are supported on arms 18 of a terminal box 19 which is mounted onthe top of a hollow post 29 through the agency of a slip fitter 21. Thetop portion of each unit assembly is held by a strap 22 shown in Fig. 1

Wiring for the lighting units is introduced through hollow post 20 intoterminal box 19 and through its arms and through the Wiring openings inthe units and their clamping washers to the terminal board in one of theunits and to the lamp sockets in each of the units. As shown in Fig. 3,the lamp socket 23 for each unit extends through the inner. closedportion of its reflector 24. This reflector is provided with a cuppedflange against which a rim of the socket rests under the biasinginfluence of a spring 25. Ribs 26 on the body portion of the lamp socketengage corresponding slots 42 in the cupped flange of the reflector, andby pressing the socket against the bias of its spring, these ribs andslots may be disengaged to rotate the socket to positions which willbring the filament of a lamp in the socket to a position in which itcoacts with the configuration of the specular surface of the reflectorto give the desired light distribution. The fi1a ments in tratfic signallamps such as this are customarily in the shape of a located in a planetransverse to the lamp axis, and the desired light distribution isgenerally obtained with the open end of the: C-sh-aped filament in theuppermost position. When the filament is properly positioned, the socketmay be released to the bias of spring 25 so that its ribs will againengage the slots in the reflector and hold the socket in adjustedposition. The fixture may be prefocused so that a lamp in its socket hasits filament in the focal plane of the reflector whose specular surfacemay be dividedinto parabolic areas giving a desired light distribution.

The reflector 24 of a lighting unit is mounted in its housing throughthe agency of a ring-shaped gasket 27 which provides a seal between themand also provides a seal between the reflector and lens of the doorstructure when the door is closed. This gasket is detachably mounted onthe reflector and the housing and is preferably formed of a flexiblematerial such as neoprene but obviously may be formed of othermaterials. In the arrangement illustrated, the gasket is an integralring and requires flexibility for mounting on the reflector as describedbelow. However, by using a split-ring construction, nonflexiblematerials or materials having slight flexibility may Other than ninetydegree be used. Gasket 27, reflector 24, and housing 1, which comprisethe assembly, are each provided with cooperating indexing means whichensure that the reflector is properly positioned in the housing. Thisarrangement is required because of the light distribution produced bythe specular surface of the reflector. The detachable gasket mounting ofthe reflector in the housing makes it easy to disassemble the parts asshown in Fig. 3 in order to gain access to the interior of the housingfor installing or changing the wiring and for adjusting the lamp socketin the reflector. When the door of a unit is in its closed positiongasket 27 forms a seal between the reflector 24 and the lens 5 byengaging it about a peripheral area thereof adjacent the rim portion ofthe lens. This lens may have varying configurations and may have bandsof prisms on its inner surface which depress and spread horizontally thelight directed therethrough by reflector 24.

As shown in Figs. 3 and 4, the housing of the lighting unit has acircular projection 28 angularly disposed to the opening in its face,and this projection is provided with circumferentially spacedrectangular notches 29 and 30 which are of unequal width. The inturnedlip or projection 28 of the housing provides a ring-shaped seatingsurface for the corresponding ring-shaped mounting surface 31 of gasket27, and in the arrangement illustrated notches 29 and 30 do not extendfor the full depth of the projection 28 so that the mounting surface 31of gasket 27 may form a tight seal at these notches. Gasket 27 isprovided with rectangular tabs 32 and 33 which are circumferentiallyspaced about gasket 27 in accordance with the spacing of notches 29 and30 in the inturned projection 28 of housing 1. These tabs 32 and 33 arealso of different widths corresponding respectively to the Widths ofnotches 29 and 30 in projection 28 of housing 1 so as to index thegasket relative to the housing. Each tab is separated at correspondingends from mounting surface 31 of the gasket to form slots 34 with closedinner ends and of a width corresponding to the thickness of the angularprojection 28 of the housing. Thus, by inserting gasket 27 into housing1 with its mounting surface 31 against the outer surface of projection28 and with tabs 32 and 33 in register with notches 29 and 30 inprojection 28, the gasket may be latched in position by rotating it in aclockwise direction in order to bring the tabs in locking engagementwith projection 28 which is engaged at the notches by slots 34 in thetabs.

Gasket 27 is also provided circumferentially of its inner surface with areflector holding groove 35 which engages a circular flange 36 whichextends outwardly from the outer portion of a cylindrical strip 37formed about the open mouth of the reflector. Gasket 27 also has on theinner side of groove 35 a surface 38 which engages and seats againstcylindrical side wall portion 37 of the reflector. Mating configurationsare provided on the reflector and gasket in order to index the positionof the reflector relative to tabs 32 and 33 of the gasket. In thearrangement illustrated, a projecting tongue 39 is formed on rim 36 ofthe reflector and engages a socket formed at 4B in the gasket at thebottom of its groove 35. Since in some assemblies the lighting unit mayform part of a group having a horizontal position instead of thevertical position shown in Fig. 1, another socket is formed therein forthe projecting tongue 39 of the reflector at a position 41 which isdisplaced ninety degrees about the optical axis of the reflector fromthe socket at 40. The positions of these sockets 4t) and 41 are clearlyindicated, as shown in Fig. '3, by projections which extend beyond thebeveled outer surface of the gasket.

The projecting front surface portion of the gasket engages the rim oflens 5 as shown in Fig. 4 when the door holding this lens is in itsclosed position covering the opening in the face of the lighting unithousing.

It thus becomes apparent that the gasket employed for mounting andorienting reflector 24 in casing 1 not only forms a seal between thesemembers through its seating surfaces engaging corresponding seatingsurfaces on these members, but also provides an engagement with the lensin the door of the unit when this door is closed. Thus the opticalsystem of the lighting unit is completely sealed against the entrance ofdust, dirt, bugs, moisture and the like and a high optical performanceof this system is guaranteed. On the other hand, the reflector may bereadily disassembled from the housing by a simple twist and pulloperation for necessary wiring operations and for adjusting the socketfor a lamp in order to position the lamp bulb therein relative to thereflector surface. Furthermore, when the door of a unit is opened, readyaccess is afforded for replacing this lamp when it becomes necessary todo this.

The principal parts of our lighting unit, such as housing 1, door ring2, visor 9 and reflector 24, may be formed of sheet metal which may bereadily formed by suitable press operations. Preferably, we form theseparts of a light metal such as aluminum or an aluminum alloy. The lensmay be readily replaced by unbolting the splitring forming the bodyportion of the door. It is to be noted that no gasket is providedbetween this lens and this ring, since none is required in view of thesealing arrangement provided by our gasket construction which in itselfseals the total optical assembly.

Various modifications of our invention are possible without in any waydeparting from the spirit and scope thereof. The gasket may take formsother than that illustrated in order to accommodate variations in theconstruction employed for the lighting unit. The gasket may be formed ofmaterials other than the neoprene or the equivalent rubber-likematerials above referred to. Other constructions of the gasket may beemployed for securing the desired indexed location of the reflector inits housing and for providing a tight seal between the housing,reflector and lens parts of the lighting unit. Obviously our inventionis of general application and may be employed in lighting units otherthan those used for traflic signaling.

Thus, while we have shown and described by way of illustration only apreferred embodiment of our invention, many modifications thereof willoccur to those skilled in the art, and we therefore wish to have itunderstood that we intend in the appended claims to cover all suchmodifications as fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. In a lighting unit a housing having an opening in its face formed byan inwardly extending flange having notches of unequal width spaced fromone another about said opening; a reflector having a specular surfaceproducing a desired light distribution about its optical axis and havingan outwardly extending flange about its open mouth and an indexingconfiguration on said flange; and a flexible gasket having a mountingsurface which engages the face of said housing and having on saidsurface positioning tabs corresponding in Width respectively with thedifferent widths of said notches in the flange of said housing, saidtabs being slotted at said mounting surface to engage said housingflange and hold said gasket with its mounting .surface against the faceof said housing when tabs and notches of corresponding widths are inregister with one another and said gasket is moved relative to saidhousing to latch said gasket to said flange of said housing and saidgasket also having a groove extending lengthwise of its inner surfaceand engaging and holding the outward extending flange of said reflectorwith said indexing configuration on said flange engaging a matingconfiguration in said groove.

2. In a lighting unit a housing having an opening in its face formed byan inwardly extending flange having notches of unequal width spaced fromone another about said opening; a reflector having a specular surfaceproducing a desired light distribution about its optical axis and havingan outwardly extending flange "about its open mouth and an indexingconfiguration on said flange; a flexible gasket having a mountingsurface which engages the face of said housing and having on saidsurface positioning tabs corresponding in width respectively with thedifferent widths of said notches in the flange of said housing, saidtabs being slotted at said mounting surface to engage said housingflange and hold said gasket with its mounting surface against the faceof said housing when tabs and notches .of corresponding widths are inregister with one another and said gasket is moved relative to saidhousing to latch said gasket to said flange of said housing and saidgasket also having a groove extending lengthwise of its inner surfaceand engaging and holding the outward extending flange of said reflectorwith said indexing configuration on said flange engaging a matingconfiguration in said groove; a door having a lens opening therein; alens in said door opening and having an exposed inner peripheral areaadapted to engage said gasket; and means for holding said door closedover the opening in said housing with said peripheral area of said lensin engagement with said gasket.

3. A lighting unit comprising a housing having a circular openingtherein formed by a projection angularly disposed to the face thereof;said projection being provided with notches of unequal width spaced fromone another circumferentially of said projection and of a depth lessthan the width of said projection; a reflector within said housinghaving a specular surface producing a desired light distribution aboutits optical axis and having an open mouth defined by a cylindrical sidewall strip having an outwardly directed circular flange provided with anindexing tongue which projects beyond the edge of said flange; a doorhaving a circular lens opening therein; a circular lens mounted in saiddoor opening, means for hinging said door to swing from, a positionuncovered the opening in said housing to a closed position covering saidopening and for latching said door to said housing in its closedposition; and a flexible ring-shaped gasket having a projecting frontsurface portion which engages an inner peripheral area of said lens whensaid door in which it is mounted is closed and latched to said housing;said gasket having at its inner end a mounting surface provided withpositioning tabs corresponding in width respectively to the Widths ofsaid notches in said angular projection of said housing against whichsaid mounting surface is seated when said tabs and said notches of equalwidth are in register with one another, said tabs being separated atcorresponding ends from said mounting surface to form slots with closedinner ends and of a width corresponding to the thickness of said angularprojection of said housing for latching said mounting surface seatedagainst said angular projection when said gasket is rotated relativethereto; and said gasket also having in its inner surface areflector-holding groove which engages the flange of said reflector; asocket which extends beyond the inner surface of said groove andaccommodates said tongue which projects from said reflector flange toindex said reflector relative to said gasket and its said tabs; and aseating surface to one side of said groove which engages saidcylindrical side wall strip of said reflector.

4. A lighting unit comprising a housing having a circular openingtherein formed by a projection angularly disposed to the face thereof;said projection being provided with notches of unequal width spaced fromone another circumferentially of said projection and of a depth lessthan the width of said projection; a reflector within said housing andhaving an open mouth defined by a cylindrical side wall strip having anoutwardly directed circular flange provided with an indexing tonguewhich projects beyond the edge of said flange; said reflector having areflecting surface providing a desired light distribution relative tosaid indexing tongue; a door having a circular lens opening therein; acircular lens mounted in said door opening; means for hinging said doorto 7 swing from a position uncovering the opening in said housing to aclosed position covering said opening and for latching said door to saidhousing in its closed position; and a flexible ring-shaped gasket havinga projecting front surface portion which engages an inner peripheralarea of said lens when said door in which it is mounted is closed andlatched to said housing; said gasket slots with closed inner ends and ofa width corresponding to the thickness of said angular projection ofsaid housing for latching said mounting surface seated against saidangular projection when said gasket is rotated relative thereto; andsaid gasket also having in its inner surface a reflector-holding groovewhich engages said circular flange of said reflector; a plurality ofsockets positioned at ninety degrees from one another along said grooveand extending beyond the inner surface of. said groove, each of saidsockets being of a size to accommodate said tongue of said reflectorwhich projects from said reflector flange and indexes said reflector ineither one of two definite positions in said gasket relative to its saidmounting tabs, and a seating surface to one side of said groove whichengages said cylindrical side wall strip of said reflector.

References Cited in the file of this patent UNITED STATES PATENTS1,336,407 Ahman Apr. 13, 1920 1,761,528 Fryberg June 3, 1930 2,615,084Diebold Oct. 21, 1952 2,725,546 Moore et al Nov. 29,1955

FOREIGN PATENTS 10,968 Great Britain Feb. 29, 1912 225,651 Great BritainDec. 11, 1924 391,212 Germany Feb. 29, 1924 478,579 Great Britain Ian.30, 1938 505,768 Great Britain May 16, 1939

